Unsaturated hydrocarbon esters of n, nu-disubstituted thionocarbamic acids



United States Patent 3,288,782 UNSATURATED HYDROCARBON ESTERS OF N,N-DISUBSTITUTED THTONOCAREAMIC ACIDS John J. DAmico, Charleston, W. Va.,assignor to Monsanto Company, a corporation of Delaware No Drawing.Filed July 25, 1962, Ser. No. 212,449 10 Claims. (Cl. 260-239) Thisapplication is a continuation-in-part of copending application SerialNo. 721,3 62, filed March 14, 1958, and

. now abandoned.

comprise a valuable family of herbicides, where A and A are preferablythe same or different acyclic radicals including alkoxy and halogensubstituted derivatives thereof, cyclohexenyl, cyclohexyl, phenyl, ortogether constitute a divalent hydrocarbon radical of 5-8 carbon atomsinclusive forming with the nitrogen .a heteroeyclic ring of at least 6but not more than 7 ring members and A represents eyclohexenyl or alower alkenyl radical. By alkenyl group is meant an open chainunsaturated radical containing one double bond. A and A include alkylbut are preferably lower alkyl, alkoxy substituted lower alkyl, halogensubstituted lower alkenyl and lower monoolefinic hydrocarbon radicalsall of which should contain at least two carbon atoms. Examples of A andA comprise 2-chloroallyl, 2-bromoallyl, 2,3-dichloroallyl,3-chloroallyl, 3-chlorobutenyl, isopropyl, butyl, isobutyl, 2-butenyl,amyl, ethoxypropyl, methoxypropyl, allyl, cyclohexyl and phenyl. Notmore than one of A and A should be carbocyclic. Examples of A" arevinyl, allyl, methallyl and cyclohexenyl.

The new toxicants may be prepared by several methods. A lower alkenylalcohol may be condensed with an N,N-dilower acyclic thioca-rbamylchloride with or without an HCl acceptor, as for example, pyridine,triethylamine or potassium carbonate. Alternatively, a lower alkenylxanthate may be condensed with sodium monochloroacetate and the producttreated with a dilower acyclic amine. Vinyl esters are obtained bycondensing an alkali metal salt of the corresponding thionocarbamic acidwith acetylene. The following examples illustrate the preparation:

Example 1 To 240.5 parts by weight (5.0 moles) of allyl alcohol wasadded in one portion 179.7 parts by weight (1.0 mole) of dipropylthiocarbamyl chloride. The exothermic reaction caused a rise intemperature from 28 to 65 C. in two minutes. The stirred reactionmixture was then heated at refluxing temperature for 24 hours, cooledat25 C. and then filtered to remove any insoluble impurities. The excessalcohol was removed by distillation. Vacuum distillation of the residuegave a 25.4% yield of allyl dipropylthionocarbamate as an amber liquid,B.P. 130132 C./6 mm. Analysis gave 6.6% nitrogen as compared to 7.0%calculated for C H NOS.

The most satisfactory and preferred procedure was carried out asfollows: To a stirred solution of 47.1 parts by weight (0.255 mole) ofsodium carbonate in 200 parts by weight of water was added 47.3 parts byweight (0.5 mole) of monochloroacetic acid to form a solution having apH of 8. The addition was carried out at a temperature of 10-20 C. overa ten minute period. Stirring was continued for minutes and then 86parts by weight (0.5 mole) of potassium allylxanthate was added in oneportion. The reaction mixture was stirred for 1 /2 hours at 15-30 C.then cooled to 10 C. and 60.8 parts by weight (0.6 mole) ofdipropylamine added in one portion. The reaction mixture was stirred for5 hours while maintaining the temperature at 25-30 C. The organic layerwhich separated was then heated in vacuo (14 mm.) at a maximumtemperature of 60 C. for 3 hours and filtered. This gave a 72.9% yieldof allyl dipropylthionocarbamate as an amber liquid. It contained 7.0%nitrogen and 16.3% sulfur as compared to 7.0% nitrogen and 15.9% sulfurcalculated fOI' CIOHIQNOS.

Example 2 In this example, 151.7 parts by weight (1.0 mole) of diethylthiocarbamyl chloride was substituted for the vdipropyl thiocarbamylchloride in the process described in the first paragraph of Example 1.The exothermic reaction caused a temperature rise from 25 to 60 C, intwo minutes. The stirred reaction mixture was then heated at 90 C. for24 hours, cooled to 25 C. and then filtered to remove any insolubleimpurities. The excess alcohol was removed by distillation. Vacuumdistillation of the residue gave an 18.5% yield of allyldiethylthionocarbamate as an amber liquid, B.P. -107 C./l0 mm. Analysisgave 8.0% nitrogen as compared to 8.1% calculated for C H NOS.

The same compound was prepared in 53% yield by the method described inthe second paragraph of Example 1 substituting 43.9 parts by weight ofdiethylamine for the dipropylamine.

Example 3 stirred for 24 hours at 25-30 C. and then extracted with A 400ml. of ethyl ether. The ether solution was washed with water untilneutral to litmus and dried over sodium sulfate. The ether was removedin vacuo at a maximum temperature of 80-90 C./12 mm, Allyldiallylt-hionocarbamate was obtained in 46.6% yield as an amber oil.Analysis gave 708% nitrogen compared to 7.10% calculated for C H NOS.

Example 4 To 23.7 grams (0.25 mole) of chloroacetic acid was added 13.6grams (0.128 mole) of sodium carbonate dissolved in 200 ml. of water togive a solution having a pH of about 8. The solution was stirred for 15minutes at 20-25 C. and then 43 grams (0.25 mole) of potassiumallylxanthate added in one portion at 23 C. The temperature dropped atfirst to 17 C. and then rose to a maximum of 31 C. After stirring thereaction mixture for one and one 'half hours, it was cooled to 10 C.Thereupon there was added in one portion, 34 grams (0.3 mole) ofN-methyl-N-cyclohexylamine causing the temperature to rise to 36 C.Stirring was continued for 5 hours and the reaction mixture thenextracted with 400 ml. of ethyl ether. The ether extract was washed.with two 200 ml. portions of water, then with 200 ml. of dilutehydrochloric acid solution, (followed by water until neutral to litmus.After drying over sodium sulfate the ether was removed in vacuo at amaximum temperature of 60 C./12 mm. AllylN-cyclohexyl-N-methy-lthionocarba-- mate was obtained in 43.2% yield asan amber oil. Analysis gave 6. 04% nitrogen compared to 6.57% calculatedfor C11H19NOS- Employing the same reaction conditions and replacingN-methyl-N-cyclohexylamine with an equi-m-olar amount, respectively, ofN-ethyl-N-cyclohexylamine and N-propyl- N-cyclohexylamine, furtherexamples were prepared possessing the following physical properties:

Example 5 Allyl Ncyclohexyl-N-ethylthionocarbamate, an amber oil, in46.2% yield. Analysis gave 5.95% nitrogen compared to 6.16% calculatedfor C H NOS.

Example 6 Allyl N-cyclohexyl-N-propylthionocarbamate, an amber oil, in44.5% yield. Analysis gave 5.68% nitrogen compared to 5.80% calculatedfor C H NOS.

Example 7 To a stirred slurry comprising 11.7 grams (0.2 mole) of allylalcohol, 30 grams of triethylamine and 150 ml. of benzene was added inone portion, 39.9 grams (0.2 mole) of N-ethyl thiocarbaniloyl chloride.The reaction mixture was heated at refluxing temperature for 5 hours andthen stirred at 25-30 C. for 18 hours. Thereupon 150 ml. of water wasadded and stirring continued for another ten minutes. The benzene layerwas washed with water until neutral to litmus, dried over sodium sulfateand the benzene removed in vacuo at a maximum temperature of 80-90 C./12mm. Allyl N-ethylthionocarbanilate was obtained as a viscous oil in 88%yield. On standing it became semi-solid. Analysis gave 6.67% nitrogencompared to 6.33% calculated for C H NOS.

Example 8 To 11.7 grams (0.2 mole) of allyl alcohol, 13.8 grams (0.1mole) of potassium carbonate and .200 ml. of heptane was added in oneportion, with stirring, 17.8 grams (0.1 mole) ofhexamethyleniminethiocarbamoyl chloride. The reaction mixture was heatedat refluxing temperature for six hours and then filtered hot. Hept-anewas removed in vacuo at a maximum temperature of 8090 C./12 mm. Al-lyl1hexamethyleniminecarbothionate was obtained as an oil in 91.6% yield.Analysis gave 6.65% nitrogen compared to 7.56% calculated for C H NOS.

The compounds of the class defined are particularly valuable aspre-emergent herbicides, but are also somewhat toxic to foilage and insome cases severely toxic to foliage. By application to vegetation ismeant either application to the soil before the plants emerge wherebythe toxicant is brought into contact with germinating seedlings or tothe foliage. The toxicants may be applied to the soil or to foliageconveniently in the form of a spray con taining the active ingredient.For pre-emergence application amounts within the range of 1 to 60 poundsper acre are recommended. The active components are insoluble in waterbut they are soluble in common organic solvents. They may be disperseddirectly in water or dissolved first in an organic solvent and thendispersed. As dispersing and wetting agents there may be employed softor hard sodium or potassium soaps, alkylated aromatic sodium sulfonatessuch as sodium dodecylbenzenesu-lfonate, or an amine salt ofdodecylbenzenesulfonic acid, alkali metal salts of sulfated fattyalcohols, ethylene oxide condensation products of alkyl phenols or talloil and other dispersing and wetting agents. The herbicides may beformulated and applied as dry compositions by mixing the .toxicant witha finely divided solid carrier, as for example talc, clay, pyrophyllite,silica and fullers earth. Alternatively, the dry compositions may bedispersed in water and applied as a spray.

Further examples of the new toxicants comprise allylN-isopropyl-N-allylthionocarbarnate, allyl diisopr-opylthionocarbamate,allyl N-Z-chloroallyl-N-isopropylthionocarbamate, ylN-Z-chloroallyl-N-3-methoxypropylthionocarbamate, allyldibutylthionocarbamate, methallyl diethylth-ionocarbamate, methallyldiisopropylthionocarbamate, methallyl N isopropyl Nallylthionocarbamate, methallyl diallylthi-onocarbamate, vinyldibutylthionocarbamate, allyl l-piperidinecarbothionate, allylS-ethyl-Z- methyl-1-piperidinecarbothionate, Z-cyclohexenyldiethylthionocarbamate, allyl N-2-bromoallyl-N-isopropylthionocarbamate,allyl di(ethoxyethyl)thionocarbamate, allyldi(methoxyethyl)thionocarbamate and allyl N-methylthionocarbanilate.Also useful although not preferred is allyl N-cyclohexyl-Nbutylthionocarbamate.

Table I illustrates the pre-emergent herbicidal use of typical alkenylthionocarbamates. The ester was emulsified in water and applied as anaqueous spray. In this manner, the active ingredient at a dosage of 5pounds per acre was applied to the soil of seeded plots before theplants emerged. For convenience in recording the results a numericalrating system was used in which 0 indicated no phytotoxicity, 1 slightlytoxic, 2 moderately toxic and 3 severely toxic. The data illustrate thesevere toxicity of the alkenyl thionocarbamates to typical grasses. Thecriticality of the size of the groups on the nitrogen and unsaturationin the ester group is demonstrated by the fact that neither allyldimethylthionocarbamate nor ethyl dipropylthionocarb-amate exerted anytoxicity toward the same plants under identical conditions.

Additionally, it was observed that allyl dipropylthionocarbainateapplied as a 0.5% aqueous spray to grass foliage was severely phytotoxicthereto.

It is intended to cover all changes and modifications of the examples ofthe invention herein chosen for purposes of disclosure which do notconstitute departures from the spirit and scope of the invention.

What is claimed is:

1. A compound of the formula \where A and A are selected from the groupconsisting of cyclohexenyl, cyclohexyl, lower alkvl of at least twocarbon atoms, lower alkoxy substituted lower alkyl, lower alkenyl,halogen substituted lower alkenyl, phenyl and alkylene radicals of fiveto eight carbon atoms inclusive which with the nitrogen form aheterocyclic ring containing at least six but not more than seven ringmembers and A" is selected from the group consisting of cyclohexenyl,vinyl, allyl and methallyl.

2. A compound of the formula where A and A represent alkyl radicalscontaining at least two but not more than three carbon atoms and A"represents a lower monoolefinic hydrocarbon acylic radical.

3. A compound of the formula A ll \N--COA where A represents thecyclohexyl radical, A represents alkyl of one to three carbon atomsinclusive and A" represents the al-lyl radical.

4. A compound of the formula NC0-A" where A, A and A" represent lowermonolefinic acyclic hydrocarbon radicals.

5. A compound of the formula where A is an alkylene radical containingat least five but not more than eight carbon atoms forming :with thenitrogen 21 heterocyclic radical of at least six 'but not moreReferences Cited by the Examiner UNITED STATES PATENTS 2,650,876 9/1953. Stewart 2611-2914 2,691,635 10/1954 Harris et a1 260455 2,723,98911/1955 Harman 260-455 2,744,898 5/1956 Harman et a1. 260293.482,919,182 12/1959 Harman et al 260455 2,992,091 7/1961 Harman et al260293.4 3,078,153 2/1963 Harman et 'al. 260293.48

0 ALEX MAZEL, Primary Examiner.

NICHOLAS S. RIZZO, Examiner.

M. E. UPSON, A. D. ROLLINS, Assistant Examiners.

1. A PROCESS FOR HARDENING GELATIN WHICH COMPRISES REACTING THE GELATINWITH A COLORLESS COMPOUND WHICH CONWHERE A AND A'' ARE SELECTED FROM THEGROUP CONSISTING OF CYCLOHEXENYL, CYCLOHEXYL, LOWER ALKYL OF AT LEASTTWO CARBON ATOMS, LOWER ALKOXY SUBSTITUTED LOWER ALKYL, LOWER ALKENYL,HALOGEN SUBSTITUTED LOWER ALKENYL, PHENYL AND ALKYLENE RADICALS OF FIVETO EIGHT CARBON ATOMS INCLUSIVE WHICH WITH THE NITROGEN FORM AHETEROCYCLIC RING CONTAINING AT LEAST SIX BUT NOT MORE THAN SEVEN RINGMEMBERS AND A" IS SELECTED FROM THE GROUP CONSISTING OF CYCLOHEXENYL,VINYL, ALLYL AND METHALLYL.